The answer is Antwun Echols, who Hopkins defeated in 1999 to retain his IBF middleweight title before repeating the victory via stoppage the following year. 

In a lengthy career that saw him challenge for the world title on numerous occasions, Echols earned a reputation as a no-nonsense puncher who competed against top names such as Charles Brewer and Anthony Mundine.  

Despite his two defeats to Hopkins, Echols, who passed away in 2023, has been credited by Hopkins as being the most powerful opponent he faced. 

“He was clubbing, not swift. Thumping,” said Hopkins when speaking to The Ring regarding Echols’ power. 

“Also, Felix Trinidad, but that’s all. He was really one dimensional. He had great success fighting one-dimensional people. That’s not a knock on him but when you run into a Bernard Hopkins, who’s more than one dimensional, then you got a problem. 

“Kovalev was a big puncher but I’m going to stick with Antwun Echols, he could crack.”